Chinese herbal medicine for functional constipation: a randomised controlled trial

1. This was an 18-week prospective, randomised, double-blind, placebo-controlled clinical study on a Chinese herbal medicine--ma zi ren wan (MZRW)--for the treatment of functional constipation. 2. 120 subjects with functional constipation (Rome III criteria) were randomised (60 per arm) into the MZRW and placebo groups. Respective responder rates for the two groups were 43.3% and 8.3% during treatment, and 30.0% and 15.0% in the follow-up period (p<0.05). The MZRW group was superior to the placebo group in terms of increased complete spontaneous bowel movement as well as reduction in severity of constipation, straining at evacuation, and use of rescue therapy. No serious adverse effects were reported. 3. The dose of MZRW (7.5 g bid) was determined in a separate clinical trial. This study entailed a dose determination study and then a placebo-controlled clinical trial and can be a good reference for future studies.